Various designs of friction welding processes and friction welding devices have been known in practice. The two workpieces to be welded together are, e.g., rotated relative to one another in frictional contact, while they are heated and plasticized in the friction area. The rotary drive is stopped after an intended period of time, as a result of which the relative rotation slows down with braking and comes to a standstill. The two workpieces are upset and connected during the slowing down. The friction process takes several seconds in prior-art friction welding process, using speeds of 1,000 rpm and more. This prior-art process is practical for identical material, or materials possessing very similar properties and has proved successful. This friction welding process cannot be used satisfactorily for the friction welding of workpieces that consist of different materials, e.g., aluminum and steel, but possess different material properties, e.g., soft or hard light metal alloys. The friction weld joints do not have the desired strength, nor a sufficiently reproducible quality.